x402-gated card-transactions endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a card-transactions resource at `/api/v1/cards/74/transactions` behind the x402 payment protocol. It accepts POST requests and requires an X-PAYMENT header carrying a USDC payment on the Base network. The x402 challenge advertises a maximum amount of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The endpoint is described by the provider simply as "Premium API Access" with no further documentation on the request body schema or response format.
The broader lowpaymentfee.com platform lists several API categories—data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities—all priced at $0.02 per call with no API keys, no rate limits, and no minimum commitments. However, the specific `/api/v1/cards/74/transactions` path does not appear in the site's public API catalog, and no documentation pages returned meaningful content beyond a wallet-connect prompt. Without request/response schemas or usage examples, the exact data returned by this endpoint is unknown. It likely relates to transaction records for a particular card resource (card ID 74), but this is inferred from the URL path alone.
Payment settles on the Base L2 network using the "exact" scheme (one-shot per-call payment). The payTo address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 and the timeout is 300 seconds.
Capabilities
Use cases
- —Retrieving transaction history for a specific card resource via pay-per-call
- —Integrating card transaction data into agent workflows without API key management
- —Programmatic access to card-level transaction records settled in USDC on Base
Fit
Best for
- —Agents that need on-demand card transaction data without subscription overhead
- —Developers wanting keyless, pay-per-request API access on Base
- —Crypto-native applications that can settle micropayments in USDC
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/74/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, no examples, and the specific endpoint path is not listed in the provider's own catalog. Effectively a stub with only the x402 challenge to go on.
Warnings
- —No request body schema or response schema documented anywhere
- —The /api/v1/cards/74/transactions path does not appear in the provider's public API catalog
- —All documentation pages (docs, api, pricing, README) returned only a wallet-connect prompt with no content
- —Purpose and data returned by this endpoint are inferred solely from the URL path
Citations
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/cards/74/transactions
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/cards/74/transactions
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The provider lists API categories including Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com